Inferior Vena Cava Filters: The Longer They’re In, the Higher the Risk of Adverse Events

Retrievable inferior vena cava (IVC) filters are often left in place despite US Food and Drug Administration (FDA) recommendations that they be removed when they are no longer needed. Now research is suggesting that the longer they’re left, the riskier retrieval becomes. According to a new meta-analysis, retrieval attempts for filters with a “dwell time” of more than 7 months face a failure rate of greater than 40%.

“The message is that if you have a patient who’s had a filter in for 7 months or longer, really consider that they may need more than a standard technique and consider referral for advanced retrieval,” said the study’s lead author, Kush R. Desai, MD (Northwestern University Feinberg School of Medicine, Chicago, IL), in an interview with TCTMD.

Although the FDA cleared the devices to be permanent, the agency issued a safety communication in 2010 following reports of adverse events including device migration, embolization, filter fracture, lower limb deep vein thrombosis, and IVC occlusion that recommended IVC filters be removed when possible. How many of those events were related to prolonged dwell times is not known. In a quantitative decision analysis published in the Journal of Vascular Surgery: Venous and Lymphatic Disorders in October 2013, researchers from the FDA noted that “the benefit/risk profile begins to favor filter removal between 29 and 54 days after implantation.”

Advanced Techniques Improve Success Rate

For the new study, published online June 12, 2017, ahead of print in Circulation: Cardiovascular Interventions, Desai and colleagues analyzed data from 762 retrieval procedures carried out between from 2009 and 2015 at their institution. A wide range of filters were included, with the most common being Celect (Cook Medical; n = 430).

Overall, standard retrieval techniques were successful in 82% of patients and failed in 18%. With advanced techniques employed for failures, the total success rate of retrieval was 98%. An analysis looking at dwell time in relation to failure identified 7 months as a diverging point in success rates. The risk of standard technique failure beyond this point was 40.9%.

There were three major and 15 minor adverse events associated with the retrieval of filters. These included groin hematoma and injury to the inferior vena cava. In addition, one case involved fractured filter struts embedded in the caval wall that ultimately could not be removed.

“These devices were designed originally to be potentially retrievable but could be left in place,” Desai observed. “But nobody really knew what was going to happen over months and years, well past their intended application. Some of them break either due to fatigue from the way the IVC moves, . . . and in some cases we know that these patients have a higher risk of coagulopathies, so the filter might occlude, and when that happens it leads to a horrible quality of life.”

Desai and colleagues say contemporary data suggest that the retrieval rate of IVC filters may be as low as 8.5%. The reasons are likely multifactorial and include poor patient follow-up and/or implantation after trauma. The latter, said Desai, can result in some patients not even realizing they have a filter because they were either not told or do not remember being told.

To TCTMD, he said the current analysis should be solemn reminder to physicians to maintain close follow-up of their patients with IVC filters and to act on their removal in a timely manner. Additionally, the data should be seen as reassuring, Desai said, in that even if a filter has been in place for a long period of time, the chance of success is high with referral to a center capable of advanced retrieval techniques.